In 2017, Illinois adopted an “income shares” model to calculate the amount of child support that is to be awarded. The new law eliminates the percentages that were previously used (based on the number of minor children the couple had) and replaces it with a more complex calculation based on the combined net income of both parents to determine each parent’s child support obligation.

Under the new law, there are several factors that are used to calculate the child support award. These include:

• Other Child Support Payments: If a parent is paying court-ordered child support in a separate and unrelated case, the amount of that payment is deducted from the gross income of that parent to determine the net income for this case.
• Maintenance/Spousal Support: If spousal maintenance is awarded, the amount paid is subtracted from the gross income of the paying spouse and added to the gross income of the receiving spouse before making the child support calculation.
• Allocation of Parental Responsibility: If there is a “shared parenting” arrangement, defined by the children having at least 146 overnights per year with each parent, the number of actual overnights with each parent can be factored into the child support calculation.
• Health Expenses: Health insurance premiums and other medical costs can be added into the child support calculation. This can be a significant factor if there are children with special needs.
• Employment: If one of the parents is voluntarily unemployed or underemployed, the amount of potential income that parent has the ability to earn can be used as a factor in calculating child support.
• Tax Implications: The parent with the majority of parenting time is allowed to claim the children as dependents unless the court determines otherwise or both parties agree to allow the other parent to claim the children.